The Center of Cancer Systems Biology (CCSB) St. Elizabeth's Medical Center, Tufts Univ School of Med (TUSM), brings together diverse researchers from biological, mathematical, physical and clinical backgrounds to better understand the molecular and fissue-level events underlying cancer evolufion and development. In the three years since its founding the CCSB has matured into a well-established, deeply interactive and mulfidisciplinary cancer group which it is becoming an internafionally competifive research and training facility and research data repository in cancer systems biology Tufts CCSB has already been the recipient of two federally funded multidisciplinary Program Project Grants on carcinogenesis. Each combines mathemafical and computafional modeling with state-of the art experimental cancer biology. The first is a NASA Specialized Center of Research (NSCOR) funded to study risk of solid tumor carcinogenesis from space radiafion exposure ($10 Million;PI Dr. HIatky). The second is a DOE-funded center to study carcinogenesis risk following low-dose radiation exposure from background radiation ($7.5 million to Dr. HIatky and 1 million to Dr. Hahnfeldt for mathematical analysis of this issue). Clearly, both the PI and the Center are well-versed in running large program grants on carcinogenesis. Funding of this ICBP applicafion would provide an opportunity to connect this established CCSB with the nafional networks of ICBP-funded Centers around the country also embarking on predicfive cancer modeling and thereby contribute to the NCI directed goals of this Program. Nicolaos Madias, MD, Director of Medicine, SEMC, TUSM made deliberate strategic decisions in establishing the CCSB, recruifing Dr. HIatky as director, and the dedicafion of laboratory research space and compufing resources, as well as the subsequent expansion of her group, represents a major insfitufional investment and confinuing commitment to innovafive, cuffing edge cancer research. SEMC has backed up this research commitment with a massive expansion plan being implemented for its clinical services at the Oncology Center, involving an addifional 8,000 sq ft for Rad One and an addifional 8,000 sq ft for Medical Oncology (see support letter Dr. Madias). The breadth and depth of SEMC's commitment to this long-term strategic set of goals is clear. The confinuing strength of the intellectual, academic, and training environment is reinforced by Research faculty as well as clinical training appointments through TUSM.